Seasonal Affective Disorder; A Holistic Approach

Do you get the winter blues?

A feeling of low mood a motivation in the cooler months is something that many of us experience. The days become shorter and out light exposure is less, it seems normal to not have the same amount of energy that we doo in the warmer months. But for some, this shift between warm and cold weather can cause a dramatic shift in their physical, mental and emotional wellbeing. This is called Seasonal Affective Disorder.

What is Seasonal Affective Disorder?

The term Seasonal Affective Disorder (SAD) first appeared in the literature in 1984. It was used to describe recurrent depression that coincides with the winter months and naturally resolves in the warmer months. This condition is estimated to effect 10% of the population worldwide, and a staggering 70% of all people diagnosed with Major Depressive Disorder (MDD).

What are the Symptoms?

A person’s geographical location will determine their likeliness of experiencing SAD and how long they will suffer with symptoms throughout the year. Symptoms of SAD include:

• Hypersomnia

• Non restorative sleep

• Increased Appetite (including carbohydrate cravings)

• Weight Gain

• Low Mood

What Causes SAD?

After many years since it was first mentioned in the literature there is still not a lot that is known about the exact origin of SAD. It is possible that there are many different processes that are all contributing to the presentation of this condition. These theories are:

Low Serotonin

It has been hypothesised that low serotonin levels may contribute to the onset and symptom picture of SAD. Serotonin is a neurotransmitter (brain chemical) that assists with regulation of mood, appetite, digestion, sensory perception and wakefulness. Low levels of serotonin have been observed in patients diagnosed with SAD along with low levels of other neurotransmitters such as:  tryptophan (needed to make serotonin), norepinephrine (important for sleep, memory, attention and concentration) and dopamine (important for mood, motivation, memory and movement). It has been suggested that low serotonin levels in patients with SAD may be of genetic origin with studies suggesting that there may be genetic variations with serotonin transporters. Normally, the serotonin transporter is responsible for removing a certain amount of serotonin form the synaptic cleft. The synaptic cleft is a space between a neuron (brain cell) that secretes serotonin and a neuron that receives serotonin.  Genetic variations may cause the serotonin transporter to remove too much serotonin leaving no serotonin for the receiving neuron, and thus causing a serotonin deficiency.

Low Vitamin D

We have known two things for a long time now. One, that low vitamin D levels are associated with depressive disorders. And two, that vitamin D deficiency is highly prevalent in Australia, especially during the winter months. So, it makes sense that low vitamin D levels would contribute to the onset of SAD.  A recent study in Australia has found that health guidelines provided by the government for adequate sun exposure to prevent vitamin D deficiency are only relevant for summer and not winter months. The sun’s ultraviolet radiation (UVR) levels are consistently high during summer; however, they fall during winter, especially in locations further from the equator, like Melbourne, meaning that we need more time in the sun than is recommended and more than is feasibly possible with the winter months typically brining less available sunshine. Vitamin D plays a pivotal role in the production of serotonin and dopamine, so if levels are low with will further impact low neurotransmitter levels.

Disruption of Circadian Rhythm

Circadian rhythm describes our natural internal sleep wake cycle. This system is regulated by the presence or absence of light. When the sun sets and daylight subsides our eyes are adjusting to the darkness. This presence of darkness sends a message through our optic nerve to tell our brain to make the hormone melatonin which helps to initiate sleep. When the days become shorter in winter we are left with less sunlit hours in the day. This can cause a disruption to circadian rhythm as melatonin is being produced earlier in the day and can lead to the hypersomnia seen in SAD. The disruption of the circadian rhythm is said to also be the main cause of non-restorative sleep in SAD patients.

A Holistic Approach

A holistic approach to the treatment of SAD would be to assess what the individual cause may be for an individual. This may involve testing such as:

- Urine testing from neurotransmitter levels

- Blood tests for Vitamin D levels

- Salivary cortisol testing to help assess circadian rhythm.

Testing helps to establish the root cause of the imbalance so that it can be corrected.

To correct neurotransmitter imbalances, it will be necessary to make certain dietary changes to meet nutritional needs and nutritional supplementation may also play a role here.

Correcting vitamin D levels can be done with correct supplementation. Having vitamin D status evaluated prior to supplementation of vitamin D can be important to establish the correct dose for a patient and helps to assess if the supplement is being well absorbed in a re test.

Bright Light Therapy (BLT) is considered to be one of the best treatments available for SAD This therapy exposes the eyes to different light intensities with the aim to replicate the light intensity from the sun.